phelqn breaker mechanism for a magneto



June 26, 1956 R, E. PHELON 2,752,436

BREAKER MECHANISM FOR A MAGNETO Filed July 6, 1954 2 he 1 IN V EN TOR. RUSSELL E P/VfLO/V 77' R/VEY June 26, 1956 R. E. PHELON 2,752,436

BREAKER MECHANISM FOR A MAGNETO Filed July 6, 1954 2 Sheets5heet 2 WW W United States Patent BREAKER MECHANISM FOR A MAGNETO Russell E. Phelon, Longmeadow, Mass.

Application July 6, 1954, Serial No. 441,596

15 Claims. (Cl. 200-30) This invention relates to electric switches and more particularly to improvements in breaker mechanism for a magneto or the like.

While the switch or breaker mechanism of this invention may be applied to other electrical apparatus, it is adapted for particularly advantageous use in a magneto, and it is one object of the invention to provide a simple and economical breaker mechanism having all of its elements so arranged that the mechanism can be incorporated as a self-containing unit in a magneto construction.

An additional object of the invention is to provide breaker mechanism of the aforedescribed type which includes a substantially dustproof housing to protect the elements of the breaker mechanism from foreign materials and thereby prevent damage and/or malfunction which may be caused by dust and the like.

A further important object of the invention is to provide a self-contained beaker unit as described and which unit can easily be mounted on a magneto frame in proper gap-adjusted location with respect to the breaker actuating cam without the services of a skilled mechanic or technician.

Other objects and advantages of the invention, and particularly those objects and advantages having to do with details of construction and arrangement of parts, will become apparent to those skilled in the art from the following description of the attached drawings which, by way of example only, illustrate two specific embodiments of the invention. It will be understood that the scope of the invention is not to be limited to the particular embodiments shown and described otherwise than indicated by the claims which form a part of this speci fication.

Of the drawings,

Fig. l is a front view of a breaker structure incorporating the features of the invention and showing the mechanism mounted on a magneto frame is selected gapadjusted location with respect to a breaker actuating cam;

Fig. 2 is a rear view of the breaker;

Fig. 3 is a vertical sectional view taken as indicated by line 3-3 of Fig. 1;

Fig. 4 is a front view of the breaker structure with the cover removed from the housing and showing the breaker points closed;

Fig. 5 is a view similar to Fig. 4 but showing the breaker points open;

Fig. 6 is a view similar to Fig. 5 but illustrates means for adjusting the gap between the breaker points;

Fig. 7 is a front view of alternative form of breaker structure;

Fig. 8 is a front view of the alternative structure with the cover removed from the housing; and

Fig. 9 is a perspective view of the alternative form showing elements thereof in exploded relationship.

It will be unnecessary in describing the breaker mechanism of this invention to include a detailed description of a magneto. However, it should be understood that ice a conventional magneto, such as is used to generate voltage for the spark plugs of an internal combustion engine, ordinarily includes a core and field structure arranged to establish magnetic circuits during rotation of a shaft which may be an extension of the engine drive shaft and which in any event is driven in timed relationship with the engine. During shaft rotation, voltage is generated in the primary coil, the voltage reaching peak values in specific rotated positions of the shaft. The conventional breaker mechanism associated with such a magneto includes a pair of switch contacts or points connected in circuit with the primary coil and also includes actuating means adapted to separate the points when peak voltage is established in the primary coil, thereby generating high voltage in the secondary coil which is connected with the spark plugs.

In accordance with the present invention, the elements of the breaker mechanism are all arranged and supported within a housing 10 which is adapted to be adjustably mounted on a wall 12 forming a part of the frame or housing of a conventional magneto. The engine-driven shaft forming a part of the magneto projects through the wall 12 and is indicated by reference numeral 14. The projecting portion of the shaft 14 fixedly supports and rotates a cam 16 having a substantially circular peripheral portion 18 and a flat peripheral portion 20 which is at a lesser radial distance from the axis of the shaft 14 than is the circular portion 18. As will be more fully set forth hereinafter, the breaker housing 10 is adjustably mounted on the wall 12 so that its location with respect to the shaft 14 and cam 16 can be selected to assure proper engagement between a cam follower 22 and the periphery of the cam 16 and thereby assure that electrical contacts or breaker points 24 and 26 (Fig. 4) will be properly actuated by the cam 16 for movement between closed and open positions.

Referring to the breaker mechanism in greater detail and with initial reference to the housing 10, it will be noted that the said housing includes a rear wall 28 and forwardly extending walls including a top wall 30, a bottom wall 32 and left and right side walls 34 and 36, respectively. As shown in the drawings, the rear wall 28 is disposed adjacent the magneto wall 12 and the open front face of the housing 10 is closed by a cover 38. The said cover is detachably secured in engagement with the edges of the forwardly extending walls by a screw 40 which is threaded into a tapped boss 42 (Fig. 4) projecting forwardly from the rear wall 28.

While the housing it) may be fabricated in other ways, it is preferably formed as a casting and, preferably, magnetic metal is used in its manufacture so that the said housing will serve as a conductor for a magnetic or electrical ground connection to the magneto frame 12. In casting the housing 10, a rearwardly projecting boss 44 (Fig. 2) is formed on the rear wall 28 to engage the magneto wall 12. An elongated recess or groove 46 is defined in the boss 44 to extend normal to the planes of the top and bottom walls 39 and 32 and the said groove is adapted to receive a tongue or rib 47 on the magneto wall 12 and be adjustable therealong. It will be readily understood that the housing 19 is adjusted on the magneto wall 12 by relative movement between the said tongue and groove. The housing 10 is secured in adjusted position on the magneto by means of a hold down screw 48 projecting from inside the housing through and movable within a slot 50 which is parallel to the groove 46. The said screw is threaded into a suitable tapped hole (not shown) in the magneto wall 12.

Since it is most desirable to have the cam follower 22 movable in a line extending radially of the cam 16,

. it is necessary to locate the tongue or rib on the magneto JP wall 12 so that the breaker housing It and thus the cam follower 22, is adjustable radially of the cam 16. In the specific example shown, the arrangement is such as to provide for vertical adjustment of the housing 10, and the cam follower 22 is movable in a vertical plane which includes the axis of rotation of the shaft 14 and cam 16. The cam follower 22 is generally rectangular in form and is preferably fabricated of non-magnetic material. The said follower is supported for sliding movement in a vertical plane within two bosses 52 and 54 formed in the top and bottom walls 36 and 32, respectively. The length of the follower 22 is greater than the distance between the outer surfaces of the walls 31} and 32 and the said follower is biased upwardly so that its upper end will project beyond the upper wall 39. The means biasing the follower 22 upwardly comprise a helical spring 56 seated on the bottom wall 32 and engaging one leg 58 of a substantially L-shaped bracket 60 having its other leg 62 secured to one side of the follower 22 as by one or more conducting rivets 64. On the side opposite the spring 56, the said one leg 58 of the bracket 60 supports the breaker point 24 which is thereby movable with the follower 22.

In biasing the follower 22 upwardly, the spring 56 urges the breaker point 24 toward engagement with the breaker point 26 which is located on the bottom end of a conducting rivet 66 which projects through the top wall 30. The rivet 66 has a flange 68 adjacent its bottom end which flange engages an insulating grommet or sleeve 69 located in a suitable opening in the top wall 30 and the said rivet projects upwardly therethrough. The projecting portion of the rivet is surrounded by a sheet of insulating material 70 which is laid on the top surface of the top wall 30 to insulate said top wall from one leg 72 of an L-shaped terminal bracket or post 74. The said one leg 72 of the terminal post is provided with a suitable opening to receive the projecting top end of the conducting rivet 66 which top end is peened over to secure the terminal post to the housing. The other leg 76 of the terminal post 74 has a threaded aperture receiving screw 78 for securing a wire conductor (not shown) connected to the primary coil of the conventional magneto.

When the points 24 and 26 are closed as shown in Fig. 4, the magnetic circuit including the primary coil is connected through the said points, the bracket 60 and the conducting rivets 64, 64 to a conductor-spring 80 which is secured by the rivets 64, 64 to the follower 22 on the side thereof which is opposite to the bracket 60. The said conductor-spring 80 is curved to extend from the follower 22 along the bottom wall 32 and right side Wall 36 of the housing to a terminal bracket 82 which is secured in engagement with the rear wall 28 by the hold down screw 48. As previously mentioned, the housing is grounded to the magneto wall 12. Accordingly, when the breaker points 24 and 26 are engaged or closed, the magnetic circuit which includes the primary coil of the magneto is grounded.

Obviously, the said magnetic circuit is no longer grounded when the points 24 and 26 are separated. And, as previously mentioned, it is desirable to separate the breaker points and remove ground connection so as to generate high spark voltage in the secondary coil when the voltage generated in the primary coil is at peak value, corresponding to a specific rotated position of the enginedriven shaft 14. To this end, the cam 16 is arranged on the shaft 14 so that the flat 20 will be adjacent the top end of the follower (and preferably in closely spaced relationship thereto as shown in Fig. 4) when the shaft is in the rotated position wherein peak voltage is estab lished. In such position of the cam 16, the points 24 and 26 are closed by the spring 56. Immediately after the peak voltage is generated, the cam and shaft are rotated so that the peripheral portion 18 engages the top of the follower 22 and thrusts the same downwardly tothe position shown in Fig. 5 wherein the points are open or separated. During normal operation, the shaft is rotated at a relatively high rate and the follower 22 reciprocates rapidly. A fibrous felt wiper 83 is arranged to engage and wipe the cam 16 during rotation of the shaft and cam, and said wiper is extended through a suitable opening in the top wall 32 of the housing 10 and engages the conductor-spring St to dampen undesirable vibration thereof during follower reciprocation.

It will be seen that the housing 10 must be located on the magneto wall 12 with respect to the cam 16 to provide for a proper 'or selected gap between the points 24 and 26 when the cam portion 18 engages the cam follower 22. This is accomplished by moving the housing toward the cam 16 to engage the follower 22 with the cam portion 13 and then further advancing the housing 10 the amount selected for the gap. In such further advance of the housing 10, the point 26 will be separated from the point 24 by the amount of advance while the point 24 is held against movement by engagement of the follower 22 with the cam portion 13.

In accordance with the present invention, the cam follower 22 and housing 10 are so constructed and arranged as to facilitate gap adjustment. As shown by the broken lines in Fig. 6, the follower 22 is formed initially in greater length than shown in Figs. 1 to 5 and the boss 54 on the bottom wall 32 of the housing is initially formed to project downwardly more than is shown in Figs. 1 to 5. After the breaker elements have been assembled within the housing 10, the points 24- and 26 are separated a selected distance, for example 0.020 inch, by placing a feeler or gap-adjusting gauge 84 therebetween. Then, the bottom end of the follower 22 and the projecting portion of the boss 54 are milled in a common plane P so that the bottoms of the said follower and boss will always be flush when the proper or selected .020 gap separates the points 24 and 26.

Then, in locating the housing It on the magneto wall 12 in proper gap-adjusted relationship with the cam 16, it is only necessary to engage the top end of the follower 22 with the cam portion 13 and to further advance the housing 10 until the bottom end of the said follower is flush with the bottom end of the boss 54 in the plane P. Upon locating the housing 10 as described, the hold down screw 45 is tightened to secure the housing in selected gap-adjusted position.

In further accord with the invention, the housing cover 38 is preferably provided in a gauge or thickness corresponding to the selected gap so that the said cover can be used as the feeler gauge in setting the gap during manufacture and assembly of the breaker and so it can also be used as a gauge in checking the gap when the breaker is mounted on the magneto wall 12. In this connection, the cover 38 is provided with an appendage 86 which can conveniently be inserted between the points 24 and 26 in fixing and adjusting the gap therebetween.

At this point it should be noted that by preference the cam flat 20 is located at a substantially lesser radial distance from the axis of the shaft 14 than is the peripheral portion 18 of the cam. The difference in the radial distances should be sufiicient to provide for maximum anticipated gap, adjustment. That is, the difference in the said radial dimensions should be more than any gap which may be selected for the points 24 and 26. Thus, the gap between the points may be adjusted to a maximum with out having the top of the follower 22 engage the flat 21) when the points are closed. Otherwise, the cam dimensions would control gap adjustment.

From the foregoing description, it should be understood that in accordance with the present invention the elements of a breaker structure are arranged within a housing so that the structure may be incorporated as a. self-contained unit in the construction of a magneto. Ob viously, the self-contained breaker structure will facilitate initial construction of the magneto and will also facilitate disassembly for the purposes of inspection and replacement or repair. It is important to observe that the housing and detachable cover enclosing the breaker elements prevent the ingress of dust and other foreign material which might conceivably cause malfunction of the breaker. A more specific advantage of the arrangement of the breaker elements within the housing is apparent in the ease with which the breaker structure can be adjusted to set a preselected gap. Heretofore, gap adjustment has required considerable skill and is ordinarily a time-consuming task.

While not shown in the drawings, it should be understood that the breaker embodiment of Figs. 1 to 6 can be mounted on tne magneto wall 12 in reversed position without entailing substantial modification. That is, the open front face of the housing 10 can be engaged with the magneto wall 12 and shifted therealong to selected gapadjusted position. It will only be necessary to provide notches or the like on the top and bottom walls 30 and 32 engageable with a modified tongue or rib on the magneto wall 12 to guide the adjustment of the housing. In reversing the housing 10, the hold down screw will be reversed relative to the said housing to secure the housing on the magneto wall. The detachable cover 38 may be dispensed with if the housing is mounted in reverse and the said housing and magneto wall 12 will enclose the breaker elements and prevent the ingress of foreign material.

It should also be understood that generally similar arrangements of the breaker elements and housing can be employed within the scope of the invention wherein the said breaker elements include other than a rectilinearly movable cam follower or shuttle. For example, if the breaker elements include the well known oscillatable cam follower in place of the shuttle type follower 22, the said oscillatable follower can be provided with an appendage projecting through an opening in a wall of the breaker housing so as to be flush with the outer surface of the said wall when the breaker unit is located in gapadjusted position.

The alternative form of breaker structure illustrated in Figs. 7 to 9 differs from the aforedescribed structure in only one material aspect, namely, the alternative form is provided with a modified housing and cover adapted to enclose the breaker actuating cam. The modified housing 90, similarly to the first described housing 10, comprises a rear wall 92 and forwardly projecting walls including a left-hand side wall 94, a right-hand side wall 96 and a bottom wall 98. The essential modification of the housing occurs in the upper portion thereof where, instead of the previously described top wall 30, there is provided a forwardly projecting generally transverse wall 100 and there is also provided a forwardly projecting curved wall 102 which extends above the transverse wall 100 and surrounds the breaker actuating cam 104 in spaced relationship. The rear wall 92 extends only from the bottom wall 98 to the transverse wall 100 and does not extend between the said transverse wall and the curved top wall 102. Accordingly, the housing 90 may be mounted on a magneto wall (not shown) so that an actuating cam 104 will be received in the area defined within the transverse wall 100, the curved top wall 102, and the side walls 94 and 96, and the said housing may be adjusted relative to the cam for the purposes of locating a cam follower 106 in proper relationship with the cam 104 and for adjusting the gap between a pair of breaker points 108 and 110.

Similarly to the first described actuating cam, the cam 104 is provided with a generally cylindrical peripheral surface 112 and a fiat 114 and the said cam is fixed to a shaft 16 which is rotated in timed relationship with the internal combustion engine. In accordance with the previously described mode of operation, when the peripheral portion 112 of said cam engages the follower 106,

the said follower is thrust downwardly to separate the contacts or breaker points 108 and 110. The point 108 is movable with the follower 106 and is secured thereto by means of an L-shaped bracket 118. When the cam flat 114 is disposed over the follower 106, a spring 120 engaging the bracket 118 thrusts the cam follower 106 upwardly and closes the points 108 and 110. Thus, during rotation of the shaft 116 and cam 104, the cam follower 106 is reciprocated so that the points 108 and 110 are opened and closed in sequence during each revolution of the said shaft.

Similarly to the first described embodiment, a magnetic circuit including the primary coil of the magneto is opened and closed through the points 108 and 110. The connection from the coil to the point 110 is effected through a terminal bracket 122 which is secured to the housing externally thereof and in insulated relationship thereto and which is electrically connected to an internally located bracket 124 which supports the point 110. The electrical connection from the point 108 to ground is effected through the bracket 118 and one or more conducting rivets 126 extending through the follower 106 and securing the conductor-spring 128 which is electrically connected to a terminal 130. The said terminal is grounded by means of a hold down screw 132 extending through the rear wall 92 of the housing and threaded into the magneto wall similarly to the first described hold down screw 48.

While not shown in Figs. 7 to 9, the rear wall 92 of the housing 90 is provided with a boss and slot similar to the first described boss and slot 44 and 46, respectively, for engagement with a tongue or rib similar to the tongue 47 on the magneto wall. In accordance with the first described manner of adjustment, the housing 90 is adjusted on the magneto wall relative to the cam 104 to set the gap between the points 108 and 110 when the said points are separated. In this connection, it should be noted that the cam follower 106 is slidably supported within bosses 134 and 136 on the transverse wall and bottom Wall 98, respectively. It should also be observed that the bottom end of the follower 106 and the bottom of the boss 136 are milled in a common plane when the contacts 108 and are separated the desired or selected distance. Then, when the housing and breaker structure is adjusted relative to the cam, proper gap adjustment is obtained when the bottom of the follower 106 is flush with the bottom surface of the boss 136 at the time the top end of the follower engages the peripheral portion 112 of the actuating cam 104.

It is a feature of the alternative form of construction to provide a cover 138 which closes the housing 90 in any adjusted position thereof, while at the same time the said cover embraces the cam 104 in spaced relationship. More specifically, the cover 138 is adapted to engage and overlie the front edges of the forwardly projecting walls of the housing and is provided with an opening which encircles the cam 104 in spaced relationship. The said cover is secured to the housing by means of a screw 140 which projects through a vertically extending slot 142 in the said cover and is threaded into a tapped opening 144 defined in a boss 146 provided in the transverse wall 100. The said cover is provided with an offset car 148 along each side thereof and on opposite sides of its cam receiving opening. The said ears 148, 148 are provided to secure a generally annular felt dust seal or gasket 150 and a ring 152. The seal 150 embraces the cam 104 forwardly of the cover 138 and the ring 152 surrounds the cam 104 in spaced relationship forwardly of the seal 150. The felt seal 150 and ring 152 are provided with radially extending appendages 154 and 156, respectively, each of which is provided with a slot similar to and located over the cover slot 142. Thus, the screw 140 is utilized to secure the seal 150 and ring 152 when the said screw is engaged through the cover slot 142 and threaded into the tapped hole 144 in the housing 30. The seal 150 and ring 152 are additionally secured by the ears 148, 148 which are bent over and engage against the top surface of the ring 152 to clamp the said ring in the position shown in Fig. 7.

It will be readily understood that the housing 99 may be adjusted along the Wall of the magneto relative to the cam 104 to a Selected gap-adjusted position of the breaker points 108 and 116. Then, in any adjusted position of the housing 90, the cover 138, seal 150, and ring 152 are secured in place on the housing. In any adjusted position of the housing 96, the seal 150 will engage the periphery of the cam and prevent the ingress of foreign particles through the cam opening in the ring 152 and the cam opening in the cover 138. Thus, in the alternative embodiment, the area immediately surrounding the cam as well as the interior of the housing is maintained in dustproof order.

I claim:

1. In a breaker mechanism for a magneto or the like which includes a frame, a rotatable shaft and a cam f'uteu thereto, the combination of a housing having a rear wall and forwardly extending walls, a cover detachably secured to said housing to define a dust proof enclosure in cooperation with said forwardly extending walls, tongue and groove means interengaging the said rear wall of the housing and the frame for adjustment of the housing toward and away from the shaft and the cam, means for detachably securing said housing in adjusted position, one of said forwardly extending walls adjacent the cam having an opening therein, a cam follower wholly supported by said housing and snugly fitting and projecting through said opening for engagement with the cam, means biasing said follower into engagement with the cam and cooperating with the cam to cause reciprocation of the follower during each rotation of the cam, a first electrical contact fixed to said follower for movement therewith within said housing, and a second electrical contact fixedly supported within said housing for engagement by said first contact during each reciprocation of the follower.

2. In a breaker mechanism for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination of a housing having a rear wall and forwardly extending walls, a cover detachably secured to said housing to define a dust proof enclosure in cooperation With said forwardly extending walls, tongue and groove means interengaging the said rear wall of the housing and the frame for adjustment of the housing toward and away from the shaft and the cam, means for detachably securing said housing in adjusted position, one of said forwardly extending walls adjacent the cam having an opening therein, a cam follower wholly supported by said housing and snugly fitting and projecting through said opening for engagement with the cam, means disposed in said housing and biasing said follower into engagement with the cam and cooperating with the cam to cause recipr'ocation of the follower during each rotation of the cam, a first electrical contact fixed to said follower for movement therewith within said housing, and a second electrical contact fixedly supported within said housing for engagement by said first contact during each reciprocation of the follower.

3. In breaker mechanism for a magneto or the like which includes a frame and movable breaker actuating means, the combination comprising support structure detachably secured to the frame for adjustment toward and away from the shaft, a member movably supported by said support structure and engageable with said actuating means which movable member is adjustable with respect to said support structure when said support struc ture is adjusted on the frame with said movable member in engagement with the actuating means, means biasing said movable member into engagement with the actuating means and cooperating with the actuating means to cause reciprocation of the movable member, a first electrical contact fixed to said movable member for movement therewith, and a second electrical contact fixedly supported for engagement by said first contact during each reciprocation of said movable member and whereby the spacing between said first and second contacts can be selected for one position of said actuating means by adjustment of said support structure while said actuating means is in said one position and while said movable member is in engagement with said actuating means to thereby locate said movable member in predetermined relationship with said support structure.

4. In breaker mechanism for a magneto or the like which includes a frame and movable breaker actuating means, the combination comprising support structure detachably secured to the frame for adjustment toward and away from said actuating means and including a wall, a member movably supported by said support structure and engageable with said actuating means which movable member includes a portion projecting through said wall and adjustable with respect thereto when said support structure is adjusted on the frame with the said movable member in engagement with the actuating means, means biasing said movable member into engagement with the actuating means and cooperating with the actuating means to cause reciprocation of the movable member, a first electrical contact fixed to said movable member for movement therewith, and a second electrical contact fixedly secured to said support structure for engagement by said first contact during each reciprocation of said movable member and whereby the spacing between said first and second contacts can be selected for one position of said actuating means by adjustment of said support while said actuating means is in said one position and engaged by said movable member to thereby locate said portion of said movable member in predetermined relationship with said wall.

5. In breaker mechanism for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising support structure detachably secured to the frame for adjustment toward and away from the shaft and including a wall, a cam follower wholly supported by said support structure and engageable with said cam which follower includes a portion projecting throgh said wall and adjustable with respect thereto when said support structure is adjusted on the frame with said follower in engagement with the cam, means biasing said follower into engagement with the cam and cooperating With the said cam to case reciprocation of the follower during each rotation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported by said support structure for engagement by said first con tact during each reciprocation of the follower and where: by the spacing between said first and second contacts can be selected for one rotated position of said shaft by adjustment of the support structure while the shaft is in said one rotated position and while the follower engages the cam to thereby locate said follower portion in predetermined relationship with said wall.

6. In breaker structure for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising a housing detachably secured to the frame for adjustment toward and away from the shaft, a cam follower wholly supported by said housing for movement therewithin which follower has a first portion projecting through one wall of the housing for engagement with the cam and a second portion projecting through another wall of the housing and adjustable with respect thereto when said housing is adjusted on the frame with the first follower portion engaging the cam, means biasing said first follower portion into engagement with the cam and cooperating with the said cam to cause reciprocation of the follower during each rotation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported within said housing for engagement by said first contact during each reciprocation of the follower and whereby the spacing between said first and second contacts can be selected for one rotated position of said shaft by adjustment of the housing while the shaft is in said one rotated position and while the follower engages said cam to thereby locate said second follower portion in predetermined relationship with said other wall of the housing.

7. In breaker structure for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising a housing having a rear wall detachably secured to the frame for adjustment toward and away from the shaft and having forwardly extending walls, a cover detachably secured to said housing to engage the forward edges of said forwardly extending walls, a cam follower wholly supported by said housing for movement therewithin which follower has a first portion projecting through one forwardly extending wall of the housing for engagement with the cam and a second portion projecting through another forwardly extending wall of the housing and adjustable with respect thereto when said housing is adjusted on the frame with the first follower portion engaging the cam, means biasing said first follower portion into engagement with the cam and cooperating with the said cam to cause reciprocation of the follower during each rotation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported within said housing for engagement by said first contact during each reciprocation of the follower and whereby the spacing between said first and second contacts can be selected for one rotated position of said shaft by adjustment of the housing while the shaft is in said one rotated position and while the follower engages the cam to thereby locate said second follower portion in predetermined relationship with said other forwardly extending wall of the housing.

8. In breaker structure for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising a housing having a rear wall detachably secured to the frame for adjustment toward and away from the shaft and having walls extending forwardly of the rear wall, an elongated cam follower slidably supported in opposed forwardly extending walls which follower has one end projecting through one of said opposed walls for engagement with the cam and the other end projecting through the other of said opposed walls and adjustable with respect thereto when said housing is adjusted on the frame with the one end of the follower engaging the cam, means biasing said one end of the follower into engagement with the cam and cooperating with the said cam to cause reciprocation of the follower during each rotation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported by said housing for engagement by said first contact during each reciprocation of the follower and whereby the spacing between said first and second contacts can be selected for one rotated position of the shaft by adjustment of the housing while the shaft is in said one rotated position with said one end of the follower engaging the cam to thereby locate said other end of the follower in predetermined relationship with said other of said opposed walls.

9. In breaker structure for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising a housing having a rear wall detachably secured to the frame for adjustment toward and away from the shaft and having walls extending forwardly of the rear wall, a cover detachably secured to said housing and closing the same along the forward edges of said forwardly extending walls, an elongated cam follower slidably supported in opposed forwardly extending walls which follower has one end projecting through one of said opposed walls for engagement with the cam and the other end projecting through the other of said opposed walls and adjustable with respect thereto when said housing is adjusted on the frame with said one end of the follower engaging the cam, means biasing said one end of the follower into engagement with the cam and cooperating with said cam to cause reciprocation of the follower during each rotation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported in said housing for engagement by said first contact during each reciprocation of the follower and whereby the spacing between said first and second contacts can be selected for one rotated position of the shaft by adjustment of the housing while the shaft is in said one rotated position with said one end of the follower engaging the cam to thereby locate said other end of the follower in predetermined relationship with said other wall.

10. In breaker structure for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising a housing having a rear wall detachably secured to the frame for adjustment toward and away from the shaft and having walls extending forwardly of the rear wall, an elongated cam follower slidably supported in opposed forwardly extending walls for movement toward and away from the shaft and in a plane including the axis of rotation of said shaft which follower has one end projecting through one of said opposed walls for engagement with the cam and the other end projecting through the other of said opposed walls and adjustable with respect thereto when said housing is adjusted on the frame with said one end of the follower engaging the cam, means biasing said one end of the follower into engagement with the cam and cooperating with said cam to cause reciprocation of the follower during each rotation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported by said housing for engagement by said first contact during each reciprocation of the follower and whereby the spacing between said first and second contacts can be selected for one rotated position of the shaft by adjustment of the housing while the shaft is in said one rotated position with said one end of the follower engaging the cam to thereby locate said other end of the follower in predetermined relationship with said other wall.

11. In breaker structure for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising a housing having a rear wall detachably secured to the frame and adjustable toward and away from the shaft and having walls extending forwardly of the rear wall, an elongated cam follower slidably supported in opposed forwardly extending walls for movement toward and away from the shaft and in a plane including the axis of rotation of said shaft which follower has one end projecting through one of said opposed walls for engagement with the cam and the other end projecting through the other of said opposed walls and adjustable with respect thereto when said housing is adjusted on the frame with said one end of the follower engaging the cam, means biasing said one end of the follower into engagement with the cam and cooperating with said cam to cause reciprocation of the follower during each rotation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported by said housing for engagement by said first contact during each reciprocation of the follower and whereby said first and second contacts can be located in predetermined spaced relationship in one rotated position of the shaft with said one end of the follower engaging the cam by adjustment of the housing to effect flush relationship between said other end of the follower and the outer surface of said other opposed wall.

12. In breaker structure for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising a housing having a rear wall detachably secured to the frame for 11 adjustment toward and away from the shaft and having side walls and top and bottom walls extending forwardly of the rear wall, a cover detachably secured to said housing and closing the same along the forwardly extending edges of said side walls and top and bottom walls, an elongated cam follower slidably supported in said top and bottom walls for movement toward and away from said shaft in a plane including the az-zis of rotation of said shaft which follower has one end projecting through said top wall and engageable with the cam and the other end projecting through the bottom wall and adjustable with respect thereto when said housing is adjusted on the frame with said one end of the follower engaging the cam, means biasing said one end of the follower into engagement with the cam and cooperating with said cam to cause reciprocation of the follower during each rotation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported by said housing for engagement by said first electrical contact during each reciprocation of the follower and whereby the first and second contacts can be located in predetermined spaced relationship in one rotated position of the shaft with said one end of the follower engaging the cam by adjustment of said housing to locate said other end of the follower in fiush relationship with the outer surface of said bottom wall.

13. In breaker structure for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising a housing having a rear wall detachably secured to the frame for adjustment toward and away from the shaft and having side walls, one end wall and a transverse wall all extending forwardly from said rear wall, said housing also having another forwardly extending end wall spaced above said transverse wall and surrounding the cam in spaced relationship, cover means detachably and adjustably secured to said housing and surrounding the cam which cover means closes the said housing along the forward edges of said forwardly extending walls, a cam follower movably supported by said housing and engaging said cam, means biasing said follower into engagement with the cam and cooperating with said cam to cause reciprocation of the follower during each rotation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported by said housing for engagement by said first electrical contact during each reciprocation of the follower.

14. In breaker structure for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising a housing having a rear wall detachably secured to the frame for adjustment toward and away from the shaft and having forwardly extending walls including side walls, a transverse wall and a bottom wall, said housing also including a forwardly extending top wall spaced from said transverse wall and surrounding the cam in spaced relationship, a cover detachably and adjustably secured to said housing and surrounding the earn, a sealing ring secured to said cover and surrounding and engaging the cam, a retaining ring superimposed over said cover and said sealing ring, a cam follower movably supported by said housing, means biasing said follower into engagement with the cam and cooperating with the said cam to cause reciprocation of the follower during each reciprocation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported by said housing for engagement by said first electrical contact during each reciprocation of the follower.

15. In breaker structure for a magneto or the like which includes a frame, a rotatable shaft and a cam fixed thereto, the combination comprising a housing having a rear wall detachably secured to the frame for adjustment toward and away from the shaft and having forwardly projecting walls including side walls, a bottom wall and a transverse wail, said housing also including a forwardly extending top wall spaced from said transverse wall and surrounding the cam in spaced relationship, a cover detachably secured to said housing and closing the same along the forward edges of said forwardl extending walls and surrounding the cam in s aced relationship, a sealing ring surrounding and engaging said cam forwardly of said cover, a retaining ring engaging said sealing ring and secured to said cover, an elongated cam follower slidably supported in said bottom wall and said transverse wall for movement toward and away from said cam which follower has one end projecting through said transverse wall and engageable with the cam and the other end projecting through the bottom wall and adjustable with respect thereto when said housing is adjusted on the frame with said one end of the follower engaging the earn,

7 means biasing said one end of the follower into engagcment with the cam and cooperating with said cam to cause reciprocation of the follower during each rotation of the shaft, a first electrical contact fixed to said follower for movement therewith, and a second electrical contact fixedly supported by said housing for engagement by said first electrical contact during each reciprocation of the follower and whereby the first and second contacts can be located in predetermined spaced relationship in one rotated position of the shaft with said one end of the follower engaging the cam by adjustment of said housing to locate said other end of the follower in predetermined relationship with the outer surface of said bottom wall.

References fiited in the file of this patent UNITED STATES PATENTS 1,977,288 Anderson Apr. 9, 1935 2,106,721 Chermendy Feb. 1, 1938 2,384,828 Fuston Sept. 18, 1945 2,464,779 Brownlee et al Mar. 15, 1949 2,532,000 West Nov. 28, 1950 FOREIGN PATENTS 589,292 Germany Feb. 24, 1934 

